#include <stdio.h>
#include <math.h>

void reverseSentence()
{
    char c;
    scanf("%c", &c);

    if (c != '\n')
    {
        reverseSentence();
        printf("%c", c);
    }
}

int main(int argc, char *argv[])
{
    printf("输入一个字符串: ");
    reverseSentence();
    printf("\r\n");

    return 0;
}
